To compare the efficacy of lamivudine vs. placebo vs. lamivudine followed by the combination of intron A plus lamivudine in patients with chronic hepatitis B infection who are interferon alpha non-responders. There will be two primary efficacy variables: histological response (for comparison of the monotherapy regimes) and seroconversion rates (for the comparison of the placebo and combination regimes). Complete or partial normalization of serum alanine aminotransferase (ALT) and HBsAg seroconversion will be secondary markers of efficacy